Collection ProceduresQuestion 25 of 100
A coagulation specimen is the only tube ordered and a winged blood collection set will be used. What should be done first?
a.Draw and discard a tube first to prime the tubing air space
b.Fill the citrate tube directly, since the tubing volume is negligible
c.Remove the tourniquet before attaching the citrate tube
d.Use a 25 gauge needle to slow the fill rate
Explanation
The air in a winged set's tubing displaces blood from the first tube, so a discard tube is drawn first to prime the line and preserve the 9:1 fill ratio. Filling the citrate tube directly would underfill it and falsely prolong clotting times. The tourniquet stays on until blood flow is established, and a 25 gauge needle is too small and would cause hemolysis.
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